t

t System Class

Class Precedence List:

t

Description:

The set of all objects. The type t is a supertype of every type, including itself. Every object is of type t.

satisfies Type Specifier

Compound Type Specifier Kind:

Predicating.

Compound Type Specifier Syntax:

(satisfies predicate-name)

Compound Type Specifier Arguments:

predicate-name—a symbol.

Compound Type Specifier Description:

This denotes the set of all objects that satisfy the predicate predicate-name, which must be a symbol whose global function definition is a one-argument predicate. A name is required for predicate-name; lambda expressions are not allowed. For example, the type specifier (and integer (satisfies evenp)) denotes the set of all even integers. The form (typep x ’(satisfies p)) is equivalent to (if (p x) t nil).

The argument is required. The symbol * can be the argument, but it denotes itself (the symbol *), and does not represent an unspecified value.

The symbol satisfies is not valid as a type specifier .

member Type Specifier

Compound Type Specifier Kind:

Combining.

Compound Type Specifier Syntax:

(member {object}*)

Compound Type Specifier Arguments:

object—an object.

Compound Type Specifier Description:

This denotes the set containing the named objects. An object is of this type if and only if it is eql to one of the specified objects.

The type specifiers (member) and nil are equivalent. * can be among the objects, but if so it denotes itself (the symbol *) and does not represent an unspecified value. The symbol member is not valid as a type specifier ; and, specifically, it is not an abbreviation for either (member) or (member *).

See Also:

the type eql

not Type Specifier

Compound Type Specifier Kind:

Combining.

Compound Type Specifier Syntax:

(not typespec)

Compound Type Specifier Arguments:

typespec—a type specifier .

Compound Type Specifier Description:

This denotes the set of all objects that are not of the type typespec.

The argument is required, and cannot be *.

The symbol not is not valid as a type specifier .

and Type Specifier

Compound Type Specifier Kind:

Combining.

Compound Type Specifier Syntax:

(and {typespec}*)

Compound Type Specifier Arguments:

typespec—a type specifier .

Compound Type Specifier Description:

This denotes the set of all objects of the type determined by the intersection of the typespecs. * is not permitted as an argument.

The type specifiers (and) and t are equivalent. The symbol and is not valid as a type specifier , and, specifically, it is not an abbreviation for (and).

or Type Specifier

Compound Type Specifier Kind:

Combining.

Compound Type Specifier Syntax:

(or {typespec}*)

Compound Type Specifier Arguments:

typespec—a type specifier .

Compound Type Specifier Description:

This denotes the set of all objects of the type determined by the union of the typespecs. For example, the type list by definition is the same as (or null cons). Also, the value returned by position is an object of type (or null (integer 0 *)); i.e., either nil or a non-negative integer .

* is not permitted as an argument.

The type specifiers (or) and nil are equivalent. The symbol or is not valid as a type specifier ; and, specifically, it is not an abbreviation for (or).

values Type Specifier

Compound Type Specifier Kind:

Specializing.

Compound Type Specifier Syntax:

(values ↓value-typespec)

value-typespec::={typespec}* [&optional {typespec}*] [&rest typespec] [&allow-other-keys]

Compound Type Specifier Arguments:

typespec—a type specifier .

Compound Type Specifier Description:

This type specifier can be used only as the value-type in a function type specifier or a the special form. It is used to specify individual types when multiple values are involved. The &optional and &rest markers can appear in the value-type list; they indicate the parameter list of a function that, when given to multiple-value-call along with the values, would correctly receive those values.

The symbol * may not be among the value-types.

The symbol values is not valid as a type specifier ; and, specifically, it is not an abbreviation for (values).

eql Type Specifier

Compound Type Specifier Kind:

Combining.

Compound Type Specifier Syntax:

(eql object)

Compound Type Specifier Arguments:

object—an object.

Compound Type Specifier Description:

Represents the type of all x for which (eql object x) is true.

The argument object is required. The object can be *, but if so it denotes itself (the symbol *) and does not represent an unspecified value. The symbol eql is not valid as an atomic type specifier .

Expanded Reference: t

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